<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>string、number类型</title>
		<script type="text/javascript">
            document.write(typeof "Hello World!"+ "<br>");  //string
            document.write(typeof 3 + "<br>");  //number
            document.write(typeof 3*2 + "<br>");  //NaN
            document.write(typeof false + "<br>");  //boolean
            document.write(typeof varX + "<br>");  //undefined
            document.write(typeof [1,2,3] + "<br>");  //object
            document.write(typeof {name:'Tom', age:18} + "<br>");  //object
            document.write(typeof null + "<br>");  //object
        </script>
        
	<body>
	</body>
</html>